Methods of evaluating child welfare in Indian country: an illustration

The poor quality and quantity of data collected in tribal communities today reflects a lack of true community participation and commitment. This is especially problematic for evaluation studies, in which the needs and desires of the community should be the central focus. This challenge can be met by emphasizing indigenous methods and voice. The authors provide an illustration of how to do this.     

Urban American Indian/Alaskan Natives compared to non-Indians in out-of-home care

Historically, American Indian/Alaskan Native (AI/AN) children have been disproportionately represented in the foster care system. In this study, nationally representative child welfare data from October 1999 was used to compare urban AI/AN children to non-Indian children placed into out-of-home care. Compared to non-Indian children, urban AI/AN children were older, were more often male, came from poorer homes, and were more frequently placed into group homes/ residential placements. Urban AI/AN caregivers had a greater prevalence of alcohol abuse and mental health problems compared with non-Indian caregivers.     

THE POLITICAL ECONOMY OF U.S. WHEAT LEGISLATION

Both taxpayer subsidies to U.S. wheat producers and domestic deadweight losses increased as a result of the U.S. wheat program adopted in 1985. A calculation of the costs and benefits of alternative wheat policies shows that mandatory production controls with no taxpayer expense could have made wheat producers as well off as the adopted policy. Becker's theory of competition among interest groups and Peltzman's theory of the equilibrium amount of regulation are shown to be consistent with the observed policy choice if the list of fnfected interest groups includes agricultural input suppliers and grain marketing firms.     

Testing for Additivity at Select Mixture Groups of Interest Based on Statistical Equivalence Testing Methods

Several assumptions, defined and undefined, are used in the toxicity assessment of chemical mixtures. In scientific practice mixture components in the low-dose region, particularly subthreshold doses, are often assumed to behave additively (i.e., zero interaction) based on heuristic arguments. This assumption has important implications in the practice of risk assessment, but has not been experimentally tested. We have developed methodology to test for additivity in the sense of Berenbaum (Advances in Cancer Research, 1981), based on the statistical equivalence testing literature where the null hypothesis of interaction is rejected for the alternative hypothesis of additivity when data support the claim. The implication of this approach is that conclusions of additivity are made with a false positive rate controlled by the experimenter. The claim of additivity is based on prespecified additivity margins, which are chosen using expert biological judgment such that small deviations from additivity, which are not considered to be biologically important, are not statistically significant. This approach is in contrast to the usual hypothesis-testing framework that assumes additivity in the null hypothesis and rejects when there is significant evidence of interaction. In this scenario, failure to reject may be due to lack of statistical power making the claim of additivity problematic. The proposed method is illustrated in a mixture of five organophosphorus pesticides that were experimentally evaluated alone and at relevant mixing ratios. Motor activity was assessed in adult male rats following acute exposure. Four low-dose mixture groups were evaluated. Evidence of additivity is found in three of the four low-dose mixture groups. The proposed method tests for additivity of the whole mixture and does not take into account subset interactions (e.g., synergistic, antagonistic) that may have occurred and cancelled each other out.     

Book reviews

L. Keeble and B.D. Loader (eds) Community Informatics. Shaping Computer-mediated Social Relations (London: Routledge, 2001), pp. 388, ISBN 0-415-23112-4 (pbk) £18.99.

H. Dreyfus, On the Internet: Thinking in Action (London: Routledge, 2001), pp. 136, ISBN 0-415228-077 (pbk).

D. Miller and D. Slater, The Internet: An Ethnographic Approach (Oxford and New York: Berg, 2000), pp. 217, ISBN 1-8S973-389-1 (pbk) £14.99.